JSON Validator
Validate JSON syntax in real-time. Get clear error messages with line and column numbers. Catch syntax errors before they cause problems in your application.
Enter JSON to validate
Paste, type, or drag & drop a file
How to Use
- 1Paste or type your JSON in the input editor on the left.
- 2The validator automatically checks your JSON as you type.
- 3View the validation result on the right panel with detailed error information if invalid.
- 4Use the Format button to prettify valid JSON, or copy the result as needed.
Keyboard Shortcuts
- Ctrl + Enter — Format JSON
- Tab — Insert 2 spaces
Frequently Asked Questions
What is JSON?
JSON (JavaScript Object Notation) is a lightweight data interchange format that is easy for humans to read and write, and easy for machines to parse and generate. It is commonly used for transmitting data between a server and web application.
Why should I validate JSON?
Validating JSON helps catch syntax errors before they cause problems in your application. Common issues include missing commas, unquoted keys, trailing commas, and mismatched brackets. Early validation saves debugging time.
Is my data safe when using this validator?
Validation and local Auto-Fix happen entirely in your browser. If you explicitly choose Fix with AI, the JSON and error context you provide are sent to our repair endpoint and may be processed by a configured AI provider. Use Auto-Fix for sensitive data.
What types of JSON errors can this tool detect?
This validator detects all JSON syntax errors including: missing or extra commas, unquoted property names, single quotes instead of double quotes, trailing commas, mismatched brackets and braces, invalid escape sequences, and malformed numbers.
Can I validate large JSON files?
Yes, this tool can handle large JSON files as all processing happens in your browser. However, very large files (several MB) may take a moment to parse depending on your device performance.
How does real-time validation work?
As you type or paste JSON, the validator automatically checks the syntax with a small delay (150ms) to avoid interrupting your typing. This provides instant feedback without impacting performance.
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